Facsimile terminals, or “fax machines,” are widely used in home and office environments. A fax machine typically has the following basic components: (1) a processor for managing the transmission and receipt of faxed documents, (2) a scanner for scanning a document and converting it to a digital image file, (3) a printer for printing a received image file as a document, and (4) a user interface for enabling the user to operate the device and input data, such as from send destinations.
Group 3 (G3) fax technology is currently the most widely used type of facsimile transmission. G3 technology uses methods that combine amplitude and phase modulation of an analog signal generated by modems to communicate over analog telephone lines. Typically data is compressed and run-length encoding is used to result in a transmission time of less than one minute per page. Group 3 specifications are formed by the International Telecommunication Union (ITU). The ITU identifies the standards, characteristics, and operation for facsimile devices of Group 3 digital transmission. G3 standards are identified in the ITU-T Recommendations T.30 and T.4, which are incorporated herein in their entirety.
The T.4 Recommendation is the G3 standard which specifies how image data is to be formatted for facsimile transmission and reception. The T.30 Recommendation defines a binary coded system for the data transmission procedures which are necessary for document transmission between two facsimile terminals in the public switched telephone network (PSTN). As customers are migrating to using PSTN with broadband technology networks or Internet Protocol (IP) networks for data transmission, the performance of the fax machines may be limited by the communication network. For some facsimile machines, IP or broadband networks are either poorly configured or not supported for fax transmission, thus a fax may be degraded or not sent or received. Also problematic with sending faxes over IP or broadband networks is the modification of digital signals by the communication network. The signal bits may be modified during transmission, thus limiting capabilities of the fax machines. For example, error correct mode (ECM) allows a fax machine to correct errors caused by noise in a PSTN. ECM is enabled using the signal bits. If ECM is defined as being enabled by a bit value set to “1”, and the bit value is modified or converted to “0” by the communication network, ECM will be disabled. Thus, noise cannot be corrected, and the faxes may have poor image quality. Other problems with the transmission include reduced transmission rate due to voice or audio compression. Another problem found in analog networks, supporting broadband, includes increased attenuation of the signals.
With problems such as those identified above, and the increasing popularity of IP and broadband networks, problems in fax image transmission may increase. The present application therefore provides one or more embodiments for diagnosing a communication network between faxes using an IP or broadband network, identifying the problems in the network, and aiding to correct the problems.